Impulse testing device



Oct. 9,'1934. F. KUcHAs IMPULSE TESTING 'DEVICE Filed June 10, 1932 @www IIHlI ATTORNEY Patented Oct. 9, 1934 Telephone Laboratorles," "Incorporated, New

' Bell York, N. Y., a corporation of New York Application June -10, 1932, Serial No. 616,431

7" claims. (o1. 17o-175.2)

1,840,132, T. H. Roberts, granted January s, 1932, i I.

This invention relates to impulse' testing devices and more particularly to means for measuring the length of current impulses employed in telephone systems.

Very brief closures or false closures of the means which control the transmission of the impulses may result either in the false operation or the failure to operate of the responsive apparatus depending upon said impulses. vIn accordance with the present invention, therefore, means have been provided whereby if the vexact length of an impulse is known, all impulses can be tested for this length and anything shorter than the prescribed impulse measuring interval will be detected. This is accomplished by means of a condenser-timed relaywhose time of operation may be controlled by the rate of condenser charging current through its lWinding as is fullyy described in Patent No. 1,811,858, to O. R. Miller, granted June 30, 1931. The'standard impulse time to which the time of operation of the'timed relay is adjusted functions the test circuit for a satisfactory test; any impulse shorter than standard, blocks the circuit and sounds an alarm.

This invention finds one specific embodiment in testing the impulses transmitted by full mechanical senders.` Lack of adjustment of the impulse device, due to Wear or other reasons, may result either in the production and transmission of short false impulses or inthe production and transmission of regular impulses of shorter length than required. Under such circumstances, the impulse responsive apparatus may either respond falsely or not at all tothe transmitted impulse and thereby cause an'improper setting of the cooperating equipment which depends on the response of apparatus to impulses of proper length. It is desirable, therefore, in making the test' of a sender, to detect the transmission of short false impulses as Well as'regular impulses of shorter duration than that for which the impulser of the sender is adjusted. By means of the present invention, it ispossible to accomplish both of these results and,'by such detection, causeA the subsequentl adjustment of the sender impulser before wrong numbers are produced in service.

A better conception of the-scope andpurpose of the invention Will be obtained from a Aconsideration of the following detailed description taken in connection with the attached drawing which shows a simple adaptation 'of the use of my invention with an impulse switch Vof a sender used in automatic telephone systems; `To the left of the drawing is schematically illustrated an impulse switch of the kind disclosedin Patent shown wired in, cooperation with a group-.of numerical registers and designed to transmit over the line in cooperation with these registers battery impulsesy of diiferent polarity and intensity but of uniform duration; whileyto the right of the drawing is-the receptive circuit network of my invention for detecting impulses `of Whatever polarity-and intensity transmitted but of a shorter duration than what is transmitted by said impulse switch when in proper adjustment. The designation of the thousands registers and that of the impulser switch magnet are the same as shown in the above mentioned patent and-it isiassumed for the purposeof this description that'they are operated completely vin accordance with the manner described in said patent. Since, inthis description a disclosure of the thousands registers is suicienttoillustrate the principle ofxthe invention the Wiring of the remaining switchcontacts to otherregisters is not shown butisisimply diagrammatically illus.- trated. ,f -f I The essence of. the structure of my invention is the provision of. an impulse responsive relay vfor each component element of vthe'transmitted impulse anda relay for each different kind of impulse having an operating time equal to the duration ofv theV impulse. Since in the means chosen to illustrate the invention there are three kinds of impulses involving-as many different elements either singly or in combination there are shown in the drawing-three impulse relays 100, 101 and 102 which areresponsive respectively to a positive impulse, a negative impulse and atnegative marginal impulse, that is, an impulsev `whose direction of currentlflow,isdetermined'bythe application of the n'egative vpole of the transmitting battery to conductor 116 and 'whose intensity is determined byial definiteV current value` flowing through the circuiti. Itis to be understood, however, that my invention"isnot'liinited to any kind or'time of impulses or any limiting number of elements `thereof vbut may be expanded to test any number of impulses regardless of their duration or their component elements. With these qualifications the further description of the apparatus will become evident from the detailed description of the operation of the circuit.

Assume that by: any -suitable means conductors 116 and 117 are .extended to 'ai source of impulses such as that shown' to the left lof the drawing, and that the impulseadswiteh magnetlo `isabout to be operated -to ..causethe `revolutionoi the impulse .switch. Ken-5118 is' operatedrg- The `operation of the key connects ground to the armatures of the respective impulse receiving relays 100, 101 Y and 102 and also to conductor 123, over a path from ground on the normal contacts of relay 132, normal contacts of relay 131, normal contacts of relay 112, conductor 123, top contacts of key 118 to theV armatures of relays 109, ,101 and ..102. This closes thefollowing circuits: (1) rvground on armature and back contacts of relay`100, back contacts of 103, winding of relay 104 to battery. Relay 104 operates and closes a locking path for itself through the winding of relay 105 and its own Ycontacts to ground on the contacts ofrelay 113.

Relay 105 does not operate, however,v due to the short-circuiting ground on the other side of itsv winding from the back contacts of relay 103. Relay 103, which is in parallel with relay 105, likewise, does not operate for the same reason. (2) In the same way ground is extended from the back contact of relay 101, back contacts of relay 106, winding of relay 107 tobattery, operating this relay and establishing a short circuit for relays 108 and 106 from ground on the back contacts of relay 114. (3) Similarly ground is likewise extended from the back contacts of relay 102, back contacts of relay 109, winding of relay 110 to battery, operating this relay and establishing a short circuit for relays 111 and 109 from ground through the contacts of relay 115. With relays 104, 107 and 110 operated the testing device is conditioned to test the length of the incoming impulses.

The impulses generated by the switch are transmitted, according to the above mentioned patents to Roberts, in the following order: (1) positive impulse or blank, (2) negative or negative marginal impulse, (3) positive or blank, and (4) negative or negative marginal. As described more fully in the above mentioned patent, the duration of each impulse is governed by the rotationof the switch and the time of commutation between the switch cam and cooperating brush through which the impulse circuit is carried. Before the switch begins to rotate, relays v1221, 1503.l and 2160 are operated and the first impulse, .which is assumed to be positive by Virtue of the operated registers, is traced'asy follows: Source of negative battery through high resistance 120, upper contact of cam 119, Lfront contact of thousands register relay 1221, back contact of relay 1223, upper contact of cam 121, top contacts of relay ,1503, top contacts of relay 2160, conductor 116, windings of relays 100, 101 and 102, respectively, conductor 117, bottom contacts of relays 2160 and 1503, bottom contacts of cam 122 to ground. The polarity of this impulse of current is proper for the operationy ofrelay 100 but not for relays 101 and 102both of which are negatively polarized. Relay 100 operates over this lirnpulse circuit and connects ground to an impulse receiving register of anysuitableknown construction to record the reception of impulses such, as for example, the one disclosed in Patent No. 1,844,147 to E. H. Clark and issued February 9, 1932. In the meanwhile the removal of ground from the back contact of relay 100 removesthe short circuit around relays 103 and 105 which now operate. Relay 103 extends the back contact of relay 100 to conductor 124 and thence to the winding of re1ay 112. Since, however, relay 100 is operated and its back contact is opened, relay 112 does not operate at this time. Y

It will be observed that relay 113 is polarized and has two windingsthe upper one of which is in series with variable condenser125. Hence with relay 105 normal and key 118 operated the ground from the lower contacts of the key is extended over the back contacts of relay 105 to resistance V128, which is connected in parallel with both windings of relay 113. The same thing is true with relays 114 and 115 both of which arepolarized, each` has a variable condenser in series with its respective upper winding and all have ground from the lower contacts of key 118 connected to their respective windings. Consequently with the short circuit of the battery connected to one side of resistance 128 by the ,aforesaid ground, a charging circuit is established for condenser 125 from the ground through the top v"winding of relay 113, condenser 125, resistance 129 to battery while another circuit is established through the lower winding of relay 113 from the aforesaid ground, lower winding of relay 113, resistance 129 to battery. The current flow through this lower winding is in a direction not to operate the relay. The current owing through the charging condenser, however, is in a direction to charge it but its charging strength is not enough to overcome the magnetic force produced by the current through' the lower winding so that relay 113 remains normal. When, however, relay 105 operates at the beginning of an impulse, direct ground is disconnected from resistance 128 and applied over the front contact of relay 105 to the other side of condenser 125 and also to resistance 129. The eiTect of this transposition of ground is to reverse the current flow through the lower winding of relay 113 in a direction to operate it and alsoprovides a discharge path forY the energy stored in the condenser. This discharge current, however, is in a direction to oppose the direction of the current through the lower winding sothat, for an interval, the currents neutralize each other until the discharge current through the condenser is dissipated to the point where the magnetic force of the current through the lower winding can overcome its further effects and thereby cause relay 113 to operate. The time during which the relay remains normal after relay 105 is operated, that is, from the may be varied in accordance with the time de` sired to, have relay 113 remain normal after relay 105 has operated. Assuming, however, that the capacity of condenser 125 has been selected with respect to some known time interval which is to measure the standard length of transmitted impulses, then, so long as relay 100 remains operated for a length of time equal to or greater than the standard impulse, the time taken to discharge condenser 125 will be exceeded by the impulse time of relay 100. As already mentioned, the direction of current flow through the lower winding of relay 113 is such as to cause said relay to operate, so that each time impulse relay 100 isV operated for a longer time than the time it takes to discharge condenser 125, relay 113 will operate before relay 100 releases. The operation of relay 113 releases relays 105, 104 and 103, thereby disconnecting the back contact of relay 100 from the conductor 124 which extends to positive impulse alarm relay 112. When, at the termination of the impulse, relay 100 releases relay 104 will reoperate as already described and the subsequent transmission of the Shcul'df'it come; to'ps'silhowevergQthat-fthe rlength or the impulse-tran tt'ed bythe impulse 'switch 1 is v'shorter "than'fth'e f prescribed 1` standard .time interval measuredibyfth discharging time of Acondenser123, andriseqiintlyfthe operate ing .time ci relayE II3, `rla`y-100` Will release' be#A io're relay' 113 operates' 'irivvhich'fevrit ijthe-g'iouh'd connected to"the"back/contactprille-prematurely released relay' is "eirtendedf'tocnductor f i124' 'land closes' vraf'c'zircuit fuor operating -relay*"1l2 `A`which locks over -its fright ute'r contacts -to ground on `'key 3118. Over its'left contacts; relay-"112"- shortf- 'circuits 'conductorslllG-'ar-id 117 to prevent 'recepiticn ci any further' impulses; thereby? `pi''eve'ritir'i''g any disturbance vvo'fftlie test circzud:lfrmy its icondition of impulse failure." Over" its 'rig'lt' middle contacts an obvious vcircuit is closed for lighting lamp 130 thereby indicating a failure of a positive impulse while the breakingV of its right middie contact disconnects ground from the armatures of the impulse relays. Over its right inner contacts relay 112 closes ground to conductor 136. which connects with a common alarm circuit of any suitable kind to indicate the failure of the test circuit to check an impulse. rThe impulse register, on the other hand, has also ceased functioning with a failure to receive other impulses so that by comparing the condition of said register with the lighted alarm lamp, it is possible to determine precisely which impulse out of a train of impulses has not measured up to the required length.

The next transmitted impulse is either a light negative impulse or a negative marginal impulse, depending on the setting of the registers, the former causing the operation of relay 101 While the latter that of relay 102 in addition to that of relay 101. In the rst group of four impulses whether a light negative impulse or a heavy negative impulse is transmitted as a second and fourth impulse depends upon the setting of the numerical registers of the sender. The impulse switch is connected with the impulse registers in such a manner that the transmission of one or the other of the two kinds of impulses is determined in accordance with the complete description and disclosure contained in the above mentioned patent to T. H. Roberts. Assuming, however, that a light negative impulse is transmitted, then relay 101 operates in response thereto and causes the operation of relays 106 and 103 in parallel but in series with relay 107 in an identical manner as the operation of relay 100 caused the operation of relays ',105 and 103 in series with relay 104. Similarly, lif the impulse is a negative marginal one and relay 102 is operated at the same time as relay 191, relays 111 and 109 will operate in series with relay 110. Relays 114 and 115 Which are the impulse time measuring relays for the light negative and negative marginal impulses, respectively, receive the same preliminary preparation for measuring the length of their respective impulses as relay 113 received. The operation of relays 10S and 111 cause discharging circuits to be closed through condensers 126 and 127, respectively, and if either or both of these relays are still unoperated at the time when relays 101 or 102 or both are released, obvious circuits are closed for relays 131 and 132 which operate and remove ground from the armatures of the impulse relays. The former relay further closes a circuit to light lamp 134 as an indication of light negative impulse failure and the circuit to the common alarm while the latter closes a circuit ".to 4flight' lamp-*135 as* an'v4 indioat'or'l'"1"l "negativei marginal impulse failure andalso' circuit"- to *thecommonalarm. "As ffin-v the case of relay 100, a'l release "off either"v of "relays 101 `and '102""prirto-the operation'ffof' ltheir respective i Atime?"measuring relaysV` indicates -afailurev Lto `tr'an'srriit'jthe` required l standard impulse? On'the other?hand',4 ifI the impulse y relays release after the the operations'of their respective impulse measluringlfrelays 1-114 `andi -115 the`v cycle is repeated -so ilong-fasimpulses are being transmitted. 'f'

While m-'y 'i'.nv'ention" has thus Ibeen shownfdis'- vcloseolinlskeletonized form, it is 'evidentjthatf it `'can lbe'fa'dapted "incombination Withl other ele"- ments-v ofl well known -ltest circuits .which .ia're designed totest "differentfeatures'lof- 'various electrical and mechanical apparatus. `:What-is'claimed'isi i l. An impulse testing device for measuring standard impulse periods comprising impulse responsive means, circuit control means and impulse time measuring means, said last mentioned means being adapted to operate said circuit control means to stop testing. on an impulse response of less than standard duration and to continue testing on an impulse response of standard or longer than standard duration.

2. An impulse testing device comprising impulse responsive means, impulse time measuring relays, an alarm and a control circuit responsive to both said means and said relays for operating said alarm when said relays operate on an impulse shorter than that measured by said impulse time measuring relays.

3. An impulse testing device comprising a plurality of impulse responsive relays, each responsive to a diierent characteristic of an impulse, an impulse time measuring relay for each of said impulse responsive relays, a common alarm, and a control circuit for each of said impulse responsive relays and its cooperating impulse time measuring relay for operating. said alarm when said impulse relay operates on an impulse of shorter duration than the operating time of said cooperating impulse time measuring relay.

4. In an' impulse testing system, impulsing means, an impulse'responsive relay, a time measuring relay adjusted to operate in the standard time of an impulse period, a circuit for said time measuring relay, an alarm circuit, means responsive to the operation of said impulse relay for operating the circuit of said time measuring relay to measure said impulse period, by the time taken to operate said relay in said circuit, and

means responsive to the release of said impulse relay after the termination of an impulse and before the operation of said time measuring relay for closing said alarm circuit.

5. An impulse testing, device comprising a plurality of impulse responsive relays, each of said I relays being responsive to an impulse of a different character, an impulse time measuring relay for each of said impulse responsive relays, each of said impulse time measuring relays being adjusted to operate in the standard time of the impulse for which its associated impulse relay is responsive, an alarm circuit for each different character of impulse, and separate means each responsive, respectively, to each of said impulse relays for operating said alarm circuit to denote a shorter impulse than standard when any of said impulse relays operate beiore its cooperating impulse time measuring relay.

6. An impulse testing device comprising a plurality of impulse responsive relays, each of said rss lloc

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time taken by each of said relays in each of said` circuits, and means responsive to the release of any of saidimpulse relays after the termination of an impulse and before the operation of its said kcooperating time measuring relay for operating said alarm circuit. y

7. An impulse testing device comprising a plurality of impulse responsive relays, each of said relays being responsive to an impulse of a diierent character, an impulse time measuring relay for eachof said impulse responsive relays, each ofsaid time measuring relays `being adjusted to operate in the standard time of the impulse for which its associated impulse period is responsive, an indicating device for each different character -of impulse,- and separate meansvfor each of said vimpulse responsive relays and its cooperating impulse-.time measuring relay for operating said required indicating devicesto Vindicate impulse failure when each of said impulse relays operate on animpulse 'ofv shorter duration than the adjusted operating time `of its saidcooperating impulse time measuring relay. Y v- FRANCIS KUCHAS. 

